Atop the Astronomy Tower
by hmweasley
Summary: When Susan sneaks out late at night to view a meteor shower from the top of the Astronomy Tower, she isn't expecting to find Daphne Greengrass doing the same. She expects even less to be back on top of that tower months later fighting at Daphne's side.


**A/N: Written for Sapphic Season on HPFC using the prompt "time travel AU".**

**Warnings: violence and major character injuries**

**Word count: 3,898**

* * *

Cricket chirps and the occasional hoot of an owl filled the air, even at the top of the Astronomy Tower. Susan closed her eyes to soak it in. It had been ages since she'd been anywhere but the Hufflepuff common room after nightfall. With Snape and the Carrows running the castle, it had become dangerous to be out after curfew unless you wanted to receive far more than a simple detention.

Susan, who had family in vulnerable places, was the last person who wanted to be a target, but she couldn't shake her love for astronomy. She had to see that night's meteor shower, consequences be damned.

The trek to the Astronomy Tower had been long, filled with many harrowing moments of dodging out of sight of the "prefects" the Death Eaters had appointed, but she had made it without being caught. The relief was as calming as the night air.

She tilted her head back to look at the sky. Without her telescope, which had been too dangerous to bring, she couldn't make out anything as clearly as she would have liked, but there was nothing to do about that. She leaned over the edge of the tower to see as much of the sky as she could, smiling fondly at some bats that zoomed through the air in search of their next meal.

At least there was hardly a cloud in the sky. Some things had worked out for her.

"Someone felt daring tonight."

Susan's body tensed as she twirled around. Daphne Greengrass stood at the top of the stairs that led down the tower, a smirk on her lips. Susan pressed her back into the low wall that lined the top of the tower, wishing there was an alternate route of escape from the stairs Daphne was blocking.

"I wanted to see the meteor shower," she said as if that was an excuse the Carrows would find sympathetic.

Daphne shrugged and walked forward, nothing threatening about her demeanor. Susan still watched her warily, not moving an inch.

"I did too," Daphne said. "That's why I'm here. Relax, I'm not one of Snape or Carrow's pets."

Susan sighed and tried to relax, but it was difficult. While Daphne hadn't been involved in any of the infamous incidents that had happened that year, she was still a Slytherin, and as far as Susan was aware, she was friendly with some of the worst offenders. Being alone with her on top of a tower wasn't the safest situation Susan had ever been in.

But Daphne was oblivious to Susan's fear of her, or at least she seemed to be. She came to a stop right beside Susan, her face tilted towards the sky.

"This is my favourite time of day," she admitted, not looking at Susan.

Susan turned back around to look at the sky, keeping her breathing even to avoid looking like an easy target.

"Me too," she said. "Astronomy is my favourite subject. It's incredible how we can study these objects that are so far away that we can't even visit them."

Daphne hummed in agreement.

"That may be the truest thing you've ever said, Bones."

Susan raised an eyebrow. Just minutes ago, she couldn't have imagined having something in common with Daphne Greengrass. Hufflepuff had never been paired with the Slytherins for Astronomy until after O.W.L.s, and though Susan knew Daphne had chosen to take the subject at N.E.W.T.-level, she had assumed that, like many others, it was because she considered it a light subject compared to the more "serious" ones.

"Quit looking at me like you're amazed," Daphne snapped, turning her sharp gaze on Susan.

There was a glint in her eyes that hinted at amusement despite her tone. Susan gripped the railing in front of her as her stomach twisted.

"Sorry," she muttered. "It's just that Astronomy isn't usually valued much."

"You're right," Daphne said with a shrug. "It's a shame because it used to be prestigious. I'm sure you know that astronomers were some of the richest witches and wizards once upon a time. Oh how I wish that were still the case."

Susan snorted. Growing more at ease, she leant against the low wall in front of them, her elbows digging into the brick.

"You're a Greengrass. I'm sure you don't have to take money into consideration when choosing your future career."

She felt Daphne's amused gaze but refused to look at her.

"If only my parents had your attitude," Daphne said quietly after a long moment of silence.

She'd turned back to the stars by the time Susan looked at her. Susan sighed and turned to face the sky just as the first meteor streaked across it. Daphne's quiet gasp made Susan's stomach flutter, but she didn't outwardly react except to smile as more meteors appeared.

The two girls watched the show in silence, an occasional small gasp to a particularly impressive meteor the only sounds they made.

When the meteor shower was over, Susan lingered. What was the correct way to say goodbye to a somewhat enemy who you'd shared a moment such as this with? She stayed put until Daphne backed away from the wall they'd perched themselves against.

"I won't tell anyone you were here if you don't tell on me," she vowed, a challenge in her eyes as she looked at Susan.

Daphne held out her hand for a shake, and Susan eyed it warily for a moment before taking it, surprised when Daphne didn't try to overpower her in the exchange by crushing her hand. Her skin was soft, and Susan hated the pang in her chest that came when Daphne pulled away, a smirk once more on her lips as she ambled towards the staircase.

"Try not to get caught on your way back," she said over her shoulder. "I won't bail you out."

Susan watched her go with her back against the wall, unsure what to think about what had happened.

* * *

All around Susan, students cheered. Not a single soul, it seemed, wanted the Slytherins to stay and fight. No matter that they could have used all the help they could get, the idea of shooing the Slytherins from the castle thrilled those caught up in the heat of it all. Not long ago, Susan would have been one of those students, but her stomach filled with dread as she searched the Slytherin table for one person in particular.

Daphne was sitting with some of her fellow seventh years. Her eyes were wide as she listened to her housemates talk about what they planned to do next. While Susan watched her, her eyes began to roam over the rest of the hall, taking in the other students' reactions. Susan squirmed until their eyes met, and she packed every ounce of feeling she could into her expression.

She saw Daphne gasp at the look, even from across the hall.

Everyone else in the hall began moving, many to the Room of Requirement where they would be taken to safety. Susan hurried from her seat without glancing at her friends and scurried towards the Slytherin table to intercept Daphne before she made it very far.

Daphne was looking for her too. The two girls nearly collided, Daphne gripping Susan's arms to keep herself upright. Around them, students streamed about, too concerned with themselves to question the Slytherin and Hufflepuff uniting in the middle of the hall.

"Please come with me," Daphne begged. "We can hide somewhere and stay safe."

Susan stared at her. There had been countless nights atop the Astronomy Tower since their first. What had once been veiled in excuses about watching the sky had given away to midnight confessions and, eventually, much more. Susan had learned more about Daphne over the past six months than she had in the entire six years they'd known each other before that.

She saw the panic in Daphne's eyes and the tense way she held her body. The others may have cheered at the idea of all Slytherins being bigots, but Susan knew that with Daphne it was different. Susan didn't think it was the right emotion to give into, but she was more sympathetic than she once would have been as she gripped Daphne's hands in her own.

"I can't," she said. "My friends will stay to fight, and I will too. I have to. It's what's right."

Daphne sucked in a sharp breath and stared at Daphne, analyzing her in a way that had once made her deeply uncomfortable. Now she felt secure in it. She ran her thumb over the back of Daphne's hand as she waited for a response.

"Then I'll stay too."

Susan froze, her eyes widening.

"You'll what?"

"Stay," Daphne vowed. "If you are. I can't stand the idea of you fighting when I'm not there to make sure you're safe."

Without thinking about who might see them, Susan surged forward and captured Daphne's lips in a kiss. Daphne returned it eagerly, all worries about the consequences of being caught forgotten.

They could die in several hours' time, and they would make the most of what they had left.

Susan linked their hands together as they merged into the rest of the crowd who was staying. No one had time to glance at their clasped hands, let alone ask what they meant. Despite Daphne's earlier fears, she held herself high as the fighting began.

And despite Susan's earlier confidence in staying, fear gripped her heart as Death Eaters fired spell after spell at the people she cared about.

She wasn't sure how she and Daphne wound up on the Astronomy Tower lodging projectiles down at the scene below, but that was where they and some of the others were directed. It was a horrid place to be in the battle. Though no Death Eaters ascended the tower to attack them directly, spells flew up from the ground, and they saw the worst of what was happening on the grounds. Susan forced herself to dissociate from what she was seeing and focus only on the targets she could hit.

"We would end up here," Daphne whispered in Susan's ear after shooting a strong stunning spell from her wand.

Susan tried to smile back to lighten the mood, but it was useless. Her lips wouldn't make that shape when the sounds of spells hitting targets echoed through the air in ways she'd never heard before.

A stunner soared up over the Astronomy Tower and hit Daphne in the shoulder. Susan gasped as Daphne tumbled over the edge of the tower before Susan could grab ahold of her.

The others on the tower also called out, but no one could cast a spell to soften Daphne's fall in the seconds it took for her to hit the ground.

Half hanging off the tower, Susan could do nothing but stare at Daphne's limp form. Panic fogged her mind. Daphne was unreachable unless Susan tumbled off the tower herself, but Susan's arm dangled as if she might reach her if she stretched far enough.

She let out a gasp as Ginny Weasley appeared at the foot of the tower and knelt by Daphne's side. She muttered a few spells and checked her heart and breathing. Susan remained frozen in place as she watched. If spells were still being fired in their direction, she was oblivious to them.

Ginny tilted her head up to look at them and gave them a sign that everything was okay. Susan let out a sob despite knowing that 'okay' was relative. Daphne might have been alive, but after a fall like that, she was not okay.

"She'll have broken bones," Professor Sinistra said in a clipped voice.

Susan jumped, not having noticed that the professor and other students were as focused on Daphne as she was. Sinistra gripped her shoulder tightly to make sure she had her full attention.

"She'll need immediate medical attention. Madame Pomfrey keeps Skele-Gro in the infirmary. Go."

Susan didn't need to be told twice. Without so much as a nod, she ran for the infirmary.

Hogwarts had never felt as large as it did then. Susan travelled as quick as her feet would carry her, ignoring the burning in her lungs as she struggled to maintain her momentum. Her stomach twisted once she reached the Hospital Wing. She barged in without preamble.

No one was there. Anyone who had been injured hadn't had time to make it there, and Pomfrey was gone, likely treating students in the midst of the battle instead.

Susan charged through the main room to find Pomfrey's medicine closet. She frantically searched through bottles, her hands shaking. A few accidentally fell to the floor, shattering and splattering Susan's robes with their contents. She ignored them as she focused on her goal.

She let out a strangled cry as she found the Skele-Gro. Her hand, still shaking, wrapped around it, and she gripped it to her chest as she turned to go. She'd never held anything as precious as that bottle.

Rushing out of the supply closet, her robes caught on a strange silver instrument that Pomfrey kept just inside the door. Susan didn't notice it until it came crashing to the floor, exploding into a million pieces.

Susan didn't have time to gasp before the world dissolved and reformed around her.

She was no longer in the infirmary, and the Skele-Gro was no longer in her hand. She was, instead, in her dormitory surrounded by her sleeping roommates.

With a gasp, she headed for the mirror to find herself still in the pyjamas she'd worn to bed the night before.

She stood in the middle of the dormitory for a long time as her mind raced. Her roommates looked peaceful in their sleep, like the battle had been won. Susan scrambled for a clock.

It was the early morning just after sunrise. She knew it had still been late in the night moments before. She picked up her calendar to find that she hadn't yet attended any of the classes she had been in the day before the battle had broken out.

It was the previous morning.

The Battle of Hogwarts had yet to begin.

Though Susan's lungs no longer burned, her heart raced as she sat on the edge of her bed.

The instrument she'd broken was vivid in her mind. She'd never seen anything like it before, but she knew that it must have been responsible for her sudden travel through time and space.

It had sent her back, and she had no way of knowing how to return. She couldn't go to Pomfrey. Student visits to the infirmary were closely monitored by Snape and the Carrows. They'd ask her questions, and she could never tell them the truth.

She had no choice but to relive the day again without the terror of what was to come overwhelming her.

So she did.

Her classes went the same as they had earlier. Susan tapped her quill against her parchment as she restrained herself from shouting to everyone about what they were about to face. She didn't take any notes though she knew her old ones had disappeared. It didn't matter.

Harry Potter arrived, and Susan found Daphne. This time she was unsurprised when Daphne decided to stay.

When the time came, she did her best to convince Daphne not to go to the Astronomy Tower, but Daphne didn't listen as she pulled Susan up the flights of stairs.

She kept her eyes peeled for stunning spells, but none ever hit Daphne's shoulder.

Instead, Voldemort emerged from the Forbidden Forest, declaring Harry Potter's death and that the battle was over.

Susan watched with a different sort of horror as Harry's body was paraded around the castle while being tossed like a ragdoll. She reached for Daphne's hand, but Daphne shied away, shaking her head slightly as she glanced frantically between those she had fought with and Voldemort.

Susan's throat burned as she took a step away from the other girl. Bile filled her stomach.

With cackling laughter, Voldemort shot his most vicious spell yet at Harry's body. The crowd screamed as he caught fire, burning to ash before their very eyes as the Death Eaters laughed mercilessly.

Susan pressed her hands over her mouth to hold back her sobs.

"This isn't right," she muttered to anyone who would listen. "We're in the wrong timeline. This isn't right. I've messed everything up."

Daphne glanced at her with wide eyes, not sure what to make of her babbling.

Susan had been relieved when no stunning spell had come for Daphne, but now the full consequences of what had happened hit her. In their rightful time, at least they still stood a chance. Their defeat was Susan's fault.

Daphne reached for her shoulder despite shying away earlier, but Susan shook her head and knocked her hand away. She didn't deserve comfort.

"You don't understand," she said. "This isn't right. I accidentally travelled back in time, and things changed. This shouldn't be happening. He shouldn't have won."

Suddenly, she was sure that if she could just get back to the universe where Daphne had fallen, they would win the battle. Perhaps she was mistaken; she had no way of actually knowing. Yet she did.

This was her fault, even if it had been an accident.

"Susan," Daphne started, and Susan could tell right away that Daphne didn't believe her. "You're in shock."

Susan batted her hand away again, anger overwhelming her.

"Of course I'm in shock! But that doesn't change anything. I know what I saw, Daphne. I fought this battle twice, and this isn't the right timeline. We have to go back to the other...universe or whatever it was. That's the right one. This isn't right!"

Daphne wasn't any more convinced than she had been before. Susan growled in frustration.

Every cell in her body needed to do something, but she didn't know what. The Death Eaters had complete control over Hogwarts. They were corralled together into one group. She'd never make it to the infirmary, even if she'd been capable of working the machine.

She clenched her fists as she stood stoically by, waiting for Voldemort's final verdict on their fates.

* * *

In many ways, Susan escaped a terrible fate.

In the aftermath of the war, she was seen as untrustworthy by those in power, but she didn't face execution like Harry Potter's closest allies did. She kept her head low and struggled to stay out of sight.

Not everyone she cared for was as lucky, but Daphne, at least, was better off.

With Astoria having escaped with the other young students, Daphne was the only member of her family to have been present at the battle. While Voldemort wasn't thrilled with the Greengrasses for not becoming Death Eaters themselves, he accepted their sucking up with few consequences and let Daphne off the hook for the right price.

Rumor had it that he wanted to keep as many purebloods as possible. Blood traitors or not, there weren't many left. The Weasleys were the only family of the Sacred Twenty-Eight that he refused to let live, not that they'd have played along if he had.

Susan knew all of this only from the papers. She hadn't seen Daphne since the battle. At first, she had known it was for safety and was sure they would see each other again soon. But as time wore on, she grew less and less hopeful that things could get better.

It was desperation that took her to Hogwarts.

Things had taken a downward turn at the school even since Susan's seventh year. Snape had been killed in the war, leaving Alecto Carrow in charge. Many other professors had been dismissed, including McGonagall and Flitwick. Sprout, however, remained. Susan wasn't sure how her former head of house and managed it, but she was very thankful to have the connection.

No matter how much time passed, Susan knew Voldemort's victory was her fault. She needed to find that strange object stored away in the infirmary. It was the only way to make things right. Perhaps she couldn't guarantee Voldemort's downfall, but she could at least give their side a second chance.

Sprout arranged for the interview without knowing Susan's true intentions. Professors didn't last long when they answered to the Carrows, and Susan's test scores made her qualified for the role of Charms professor. Her lack of experience no longer mattered.

Her heart beat pounded in her ears as she entered the castle. She'd been sure she'd have an escort from the moment she entered, but the Carrows were too confident in their power to suspect her of wreaking havoc.

She didn't head for the headmistress' office. She hurried to the infirmary instead, focusing on her goal instead of the possibility that someone would notice her tardiness before she achieved what she needed to.

Pomfrey was still the matron, but Susan didn't see her as she slipped inside the Hospital Wing. She made the same trip she had during the battle, heading straight for the supply cabinet.

She gasped when she saw the familiar yet strange object. It looked just how she saw it in her nightmares.

Without the roar of battle in her ears, she inspected it, but she found it no less confusing than she'd found it before.

It was silver with countless knobs and handles that made no sense. Susan picked it up gingerly. With no other option, she turned a knob and was jolted through space. It felt like a portkey, but she was transported to the same Hospital Wing she'd just been in.

Her left hand grasped at air as the object disappeared from her grip. She blinked down at its shattered form on the ground.

For several seconds, she could only process her surroundings. She glanced down at her right hand to find the vial of Skele-Gro she'd once come for.

Her heart soared. Though she wasn't sure how, she'd done it. She was back in the battle. Adrenaline rushed through her veins as she remembered Daphne lying on the ground with broken bones.

Susan shot out of the infirmary with the vial clutched to her chest.

Ginny Weasley was still keeping vigil over Daphne when Susan arrived. She hardly had time to glance at Susan as she ran up to them, too busy firing off spells at Death Eaters who dared to look their way.

Susan didn't bother with greetings as she uncorked the vial and tilted its contents down the still-unconscious Daphne's throat. Daphne sputtered and came to at the same moment her bones started reforming.

She groaned and squirmed until she was half in Susan lap with her head pressed into Susan's stomach. Susan held onto her tightly as the potion worked its magic, only vaguely aware of Ginny's continued attempts to defend all three of them from the onslaught.

"It worked," Susan sobbed into Daphne's hair.

Neither Daphne nor Ginny knew just what she meant by that, but that didn't matter. Explanations could come later, once they had won and things were right with the world—or at least getting closer to it. For the moment, Daphne was healed, and they still had fighting to do. And Susan wouldn't let them lose again.


End file.
